Draft version October 23, 2017 Preprint typeset using LATEX style emulateapj v. 5/2/11 THE CIRCUM-GALACTIC MEDIUM OF MASSIVE SPIRALS II: PROBING THE NATURE OF HOT GASEOUS HALO AROUND THE MOST MASSIVE ISOLATED SPIRAL GALAXIES Jiang-Tao Li1, Joel N. Bregman1, Q. Daniel Wang2, Robert A. Crain3, Michael E. Anderson4, and Shangjia Zhang1 Draft version October 23, 2017 ABSTRACT We present the analysis of the XMM-Newton data of theCircum-GalacticMedium of MASsive Spirals (CGM-MASS) sample of six extremely massive spiral galaxies in the local Universe. All the CGM-MASS galaxies have diffuse X-ray emission from hot gas detected above the background extending ∼ (30 − 100) kpc from the galactic center. This doubles the existing detection of such extended hot CGM around massive spiral galaxies. The radial soft X-ray intensity profile of hot gas can be fitted with a β-function with the slope typically in the range of β = 0:35 − 0:55. This range, as well as those β values measured for other massive spiral galaxies, including the Milky Way (MW), are in general consistent with X-ray luminous elliptical galaxies of similar hot gas luminosity and temperature, and with those predicted from a hydrostatic isothermal gaseous halo. Hot gas in such massive spiral galaxy tends to have temperature comparable to its virial value, indicating the importance of gravitational heating. This is in contrast to lower mass galaxies where hot gas temperature tends to be systematically higher than the virial one. The ratio of the radiative cooling to free fall timescales of hot gas is much larger than the critical value of ∼ 10 throughout the entire halos of all the CGM-MASS galaxies, indicating the inefficiency of gas cooling and precipitation in the CGM. The hot CGM in these massive spiral galaxies is thus most likely in a hydrostatic state, with the feedback material mixed with the CGM, instead of escaping out of the halo or falling back to the disk. We also homogenize and compare the halo X-ray luminosity measured for the CGM-MASS galaxies and other galaxy samples and discuss the \missing" galactic feedback detected in these massive spiral galaxies. Subject headings: (galaxies:) intergalactic medium | X-rays: galaxies | galaxies: haloes | galaxies: spiral | galaxies: evolution | galaxies: fundamental parameters. 1. INTRODUCTION ture of kT ∼ 106:3 K) do we expect to find a hydrostatic, Isolated spiral galaxies are expected to host hot volume-filling, X-ray-emitting gaseous halo. gaseous halos which can be produced either by various In addition to the instability of the gravitationally types of galactic feedback or by the accretion and grav- heated gas in low- or intermediate-mass halos, another itational compression of external gas. Feedback from problem preventing us from finding the accreted hot gas AGN, supernovae (SNe), or massive stellar winds can is the contamination from feedback material. Archival produce strong X-ray emission in the halos of galaxies X-ray observations are often biased to galaxies with high with a broad range of mass (e.g., Strickland et al. 2004; star formation rates (SFRs); only a few observations were T¨ullmannet al. 2006; Li & Wang 2013a). On the other available for quiescent ones. These actively star form- hand, external gas accreted onto the galaxies can only ing galaxies eject chemically enriched gas into their ha- be heated gravitationally to the virial temperature of the los, which dominates the X-ray emission around galactic dark matter halo in massive galaxies (via hot mode accre- disks (typically within 10-20 kpc). In this case, the ac- tion, e.g., Kere˘set al. 2009). Since the radiative cooling creted gas, although significant in the mass budget, can curve of typical circum-galactic medium (CGM) peaks at only radiate in X-ray efficiently after they well mix with the metal enriched feedback material (e.g., Crain et al. kT ∼ 105−6 K where far-UV lines of highly ionized ions arXiv:1710.07355v1 [astro-ph.GA] 19 Oct 2017 2013). Therefore, in order to study the effect of gravita- emit efficiently (e.g., Sutherland & Dopita 1993), only tional heating of the diffuse X-ray emitting halo gas, we gas at X-ray emitting temperatures above this peak of prefer galaxies with low SFR. the cooling curve are expected to be stable in the halo. Extended X-ray emitting halos have been detected Therefore, only in a galaxy with mass comparable to or around various types of galaxies (see a review in Wang greater than that of the Milky Way (MW) Galaxy (with a −1 2010). The X-ray luminosity of the halo gas is typically rotational velocity of ∼ 220 km s and a virial tempera- linearly dependent on the disk SFR and is thought to be 1 Department of Astronomy, University of Michigan, 311 West mostly produced by galactic SNe feedback (e.g., Strick- Hall, 1085 S. University Ave, Ann Arbor, MI, 48109-1107, U.S.A. land et al. 2004; T¨ullmannet al. 2006; Li et al. 2008; Li 2 Department of Astronomy, University of Massachusetts, 710 & Wang 2013b; Wang et al. 2016), although sometimes North Pleasant St., Amherst, MA, 01003, U.S.A. Type Ia SNe from quiescent galaxies may play an im- 3 Astrophysics Research Institute, Liverpool John Moores Uni- versity, IC2, Liverpool Science Park, 146 Brownlow Hill, Liver- portant role (e.g., Li et al. 2009; Li 2015). Comparison pool, L3 5RF, United Kingdom with numerical simulations indicates that models could 4 Max-Planck Institute for Astrophysics, Karl-Schwarzschild- in general reproduce the X-ray luminosity of L? galaxies Straβe 1, 85748 Garching bei M¨unchen, Germany 2 J. T. Li et al. (e.g., Crain et al. 2010; Li et al. 2014). TABLE 1 On the other hand, the picture is much less clear Properties of the CGM-MASS Galaxies. for spiral galaxies significantly more massive than the Galaxy Scale M∗ M∗=LK SFR MTF MW. Although the hot CGM produced by gravitation- 11 −1 11 ally heated externally accreted gas has been predicted kpc/arcm 10 M M =L M yr 10 M UGC 12591 27.45 5:92+0:14 0.773 1:17 ± 0:13 16:1 ± 1:5 many years ago (e.g., Benson et al. 2000; Toft et al. 2002), −0:74 NGC 669 22.63 3:32+0:02 0.893 0:77 ± 0:07 5.32 there are just a few deep X-ray observations of massive −0:17 ESO142-G019 18.78 2:49+0:05 1.137 0:37 ± 0:06 5:07 ± 0:90 enough spiral galaxies whose virial temperature is in the −0:24 NGC 5908 15.10 2:56+0:02 0.842 3:81 ± 0:09 4:88 ± 0:60 X-ray range (e.g., Li et al. 2006, 2007; Rasmussen et al. −0:15 UGCA 145 20.17 1:47+0:01 0.595 2:75 ± 0:11 4.03 2009; Anderson & Bregman 2011; Anderson et al. 2016; −0:08 NGC 550 27.09 2:58+0:04 0.773 0:38 ± 0:09 5:08 ± 1:81 Dai et al. 2012; Bogd´anet al. 2013, 2015) and some of −0:28 them do not have an extended X-ray emitting halo de- tected significantly beyond the galactic disk and bulge. Updated parameters from Paper I: the stellar mass, M∗, measured We have conducted deep XMM-Newton observations of from the 2MASS K-band luminosity and the K-band mass-to-light ratio (M∗=LK) of the galaxies; M∗=LK is estimated from the a sample of five (six by adding the archival observation inclination, redshift, and Galactic extinction corrected B-V color, of UGC 12591) massive isolated spiral galaxies in the except for UGCA 145, for which the corrected B-R color is used local Universe [The Circum-Galactic Medium of MAS- (x2.1); SFR estimated from the WISE 22 µm luminosity (x2.1); sive Spirals (CGM-MASS) project]. All these galaxies the total baryon mass, MTF, estimated from the inclination corrected rotation velocity vrot and the baryonic Tully-Fisher have low SFRs compared to their large stellar masses relation (Bell & de Jong 2001), and is used to produced Fig. 9b. (Table 1). An introduction of the sample selection cri- Some other parameters of the sample galaxies, such as the −1 teria and detailed data reduction procedures, as well as distance (94.4 Mpc for UGC 12591), vrot (488:38 ± 12:54 km s 13 an initial case study of NGC 5908, are presented in Li for UGC 12591), M200 (2:42 × 10 M for UGC 12591), and r200 et al. (2016b) (Paper I). Particularly interesting is that (601 kpc for UGC 12591), are listed in Paper I. the LX=M∗ ratio of this massive isolated spiral galaxy is not significantly higher than those of lower mass non- using the same method as adopted in Paper I. We con- starburst galaxies. sider the best estimate as the integration extrapolated Here we present results from the analysis of the XMM- into the center. We assume the stellar mass estimated Newton data of the whole CGM-MASS sample, includ- without excluding the nuclear source as the upper limit ing the archival data of UGC 12591 (Dai et al. 2012). and the integration without extrapolating on to the cen- The reanalysis of this archival data is to make sure that ter as the lower limit of the estimate. All the stellar mass the data reduction and analysis processes are uniform and its upper and lower limits are calculated within an elliptical region for which the semi-major and semi-minor for all the galaxies, which is a key for statistical analy- −2 sis.